Engines, such as internal combustion engines, may often utilize fuel from a variety of sources, such as natural gas or gas produced from landfills. The chemical content or components of the fuel from the variety of sources may vary widely; however, a major component common throughout the variety of sources is methane, which provides a suitable fuel for the engines. While the variety of sources may provide a suitable fuel for the engines, combustion of the fuel may result in the formation of solid deposits within the engines. In many cases, the solid deposits may cause inadequate valve sealing, which may ultimately result in malfunction (e.g., misfiring) of the engines and/or components thereof. In addition to the solid deposits, the combustion of the fuel may often lead to increased exhaust emissions (e.g., NOx emissions) from the engines. The increased exhaust emissions may often exceed the stringent limits imposed and enforced by Government agencies, such as the United States Environmental Protection Agency (EPA).
In view of the foregoing, conventional internal combustion engines often utilize lean fuel mixtures (i.e., air and fuel mixture containing a relatively high ratio of air to fuel) in an effort to reduce the exhaust emissions. To combust the leaner fuel mixtures, however, the internal combustion engines often employ pre-combustion chambers, often referred to as pre-chambers, in fluid communication with a main combustion chamber. The pre-chambers may contain rich fuel mixtures (i.e., mixtures containing a relatively high ratio of fuel to air), and the main combustion chamber may contain the lean fuel mixtures. In operation, the rich fuel mixtures may be directed from a fuel supply to the pre-chambers via one or more valves (e.g., check valve) and combusted therein. Combustion of the rich fuel mixtures in the pre-chambers subsequently leads to the combustion of the lean fuel mixtures contained in the main combustion chamber.
While the pre-chambers have proven to be effective in reducing the exhaust emissions in conventional internal combustion engines, employing the pre-chambers may often lead to incomplete or inefficient combustion of the fuel mixtures and poor fuel economy. The incomplete or inefficient combustion of the fuel mixtures may often be attributed or traced back to the check valves configured to control a flow of the rich fuel mixtures from the fuel supply to the pre-chamber. Conventional check valves are often designed to be actuated by pressure differentials between the fuel supply and the pre-chamber. For example, during an intake stroke, the pressure in the main combustion chamber drops below the pressure in the fuel supply, creating a pressure differential therebetween. The pressure differential between the fuel supply and the main combustion chamber opens the check valve, thereby allowing a flow of the rich fuel mixtures to the pre-chamber. Further, during a compression stroke, the pressure in the main combustion chamber increases above the pressure in the fuel supply to close the check valve, thereby preventing the flow of the rich fuel mixtures to the pre-chamber. Accordingly, it may be appreciated that the flow of the rich fuel mixtures via the check valve may be crudely controlled or regulated by varying the pressures of the gas supply and/or the main combustion chambers. Crudely regulating the flow of the rich fuel mixture in this manner, however, may often lead to inconsistent concentrations, incomplete combustion, poor fuel economy, and ultimately, inefficient operation of the engines.
What is needed, then, is an improved valve for regulating a flow of fuel to pre-chambers of internal combustion engines.